I know several meowth maniacs who would be delighted to hear you say that last part.
In all seriousness, it’s just because you can control quite a bit when breeding, and Alolan meowth were bred specifically to produce a persian with those specific characteristics. The meowth stage looks similar to the standard meowth, however, simply because most Alolan breeders still think it’s cute and wanted to maintain that house cat-like cuteness through to its persian stage.
The Pokédex According to Bill 